Weldrod coating



' No Drawing.

Patented Apr. 1-1, was

UNIT STATES FREDERICK JULIUS ESSLINGER, OF PETROLEUM, HUBBARD TOWNSHIP,TRUMBULL COUNTY, OHIO, ASSIGNOR TO THE PETROLEUM IRON WORKS 00. OF OHIO,OF SHARON,

PENNSYLVANIA, A CORPORATION OF OHIO WELDROD COATING All weldrodcoverings of the prior art with which I am familiar suffer thedisadvantage that too much gas is evolved and, at any rate, that gas iscarried into the weld and not being completely removed makes for aporous deposit; that the slag because of its relatively high specificgravity does not readily sepa-- rate itself and, hence, formsundesirable and objectionable inclusions in the weld; that the slaghardens too quickly and chills at the colder melting points of weldmetal and arent metal, thus forming a groove at the juncture andundercutting the parent metal.

In extended experimentation having for its ultimate object theelimination of the defects and disadvantageous conditions aforestated, Ihave found that by following the procedure hereinafter-described andclaimed, that I can remedy the defects of the general practice andsecure remarkable results in electric fusion welding.

The nature of the invention consistsin sharply controlling the meltingpoint of the flux coating by the use of a component or components havingrelatively low melting point and having strong aflinity foracid'radicals and serving to unite .with sulphur and phosphorous and sopurify the metal of these undesirables and, withal, effective toestablish a gaseous envelope to protect the are ;'it being essentialthat there should be an excess of acid radicals around the are over thenumber of basic radicals. The acid radicals serve to combine with thebasic radicals and it is desirable that this reaction should be comlete.The acid radicals may be supplied rom glass, sodium silicate, and kaolinor its equivalent, when disassociated at high temperature. The basicradicals are supplied from sodium carbonate and ferro-manganese whendisassociated at high temperatures. The characteristic feature of thenew acid slag forming material is the use of soda ash to govern themelting point of the coating and slag and to provide the gaseousenvelope.

In the practice of the invention I prepare a fusible coating orcovering, unstable at high temperatures, containing a carbonate of analkali or alkaline earth elements together with sodium silicate, andsilicate of the alkali Applicationjfiled June 14,

and alkaline earth elements (kaolin or bauxite) and a suitabledeoxidizing agent such as ferro-manganese or aluminum, which coveringwillbe partly disassociated by the heat of the arc and will producegases which will surround the arc and protect the weld metal thefollowing ingredients in the proportions stated more or less: I

Kaolin 7 Sodium silicate 41 Glass 22 Ferro-manganese 22 Soda ash 6 Water1 2 By preference the sodium silicate is used both in the form of powderand in the form of liquid. The liquid sodium silicate has a strongalkaline reaction due to the presence of anexcess of sodium oxide'whichbecomes free to combine at high heat the same as the decompositionproduct of soda ash Na O.

The solid sodium silicate and the glass do not give off basic radicalson decomposition; the kaolin probably gives off basic and acid radicalsunder high heat. The ferro-manga nese combines with iron oxide, the irongoing into the weld. The man anese oxide combines with an acid radicaliO forming manganese silicate which goes into the slag as do the sodiumsalts. A small proportion of the manganese will alloy with the iron ofthe weld thereby increasing the tensile strength and toughness. The slagconsists of manganese silicate, iron silicate, calcium silicate, sodiumsilicate, sodium phosphate, sodium sulphate and traces of silicates ofother elements. The soda ash'(Na CO is preferably employed in the formof a dust free, granulated, dense element containing the usual or commonimpurities such as sodium chloride, sodium sulphates, calcium carbon- 21,90s,cso

ate and magnesium carbonate. The specific gravity of soda ash is 2.47 6and its melting point is about 1565 F.

Having described the invention, what is 5 claimed is:

1. A composition for coating weldrods, comprising the followingcomponents in sub stantially the proportions stated, kaolin 7., sodiumsilicate 41., glass 22., ferro-manganese 10 22., soda ash 6. and water2.

2. A weldrod having a coating formed from a plastic compositioncomprising the following components in substantially the proportionsstated, kaolin 7., sodium silicate 15 41., glass 22., ferro-manganese22., soda ash 6. and suificient moisture to effect a mixture.

In testimony whereof I aflix my signature.

FREDERICK JULIUS ESSLINGER.

